Russell Martin doesn’t have the memories to guide him. He wasn’t in New York before last season and doesn’t have a mental image of what Andy Pettitte is supposed to be. Martin only knows this version, the guy with graying hair who turns 40 next week and laughs uncomfortably when someone mentions that his son has been Tweeting about him.

“I’m surprised more with his attitude, his passion for the game and his intensity,” Martin said. “I feel like on days that he pitches, it gives a different energy to the team. It’s remarkable.”

Tonight, Pettitte was dealing. That’s the word his son used on Twitter. Against a first-place team — now tied with Baltimore — Pettitte went 7.1 shutout innings, striking out 10 and allowing just two hits. Last time he struck out 10 was exactly two years ago in Toronto. Last time he struck out 10 in the Bronx was 2003.

“I want to be a positive impact on this team,” Pettitte said. “I felt like I could be, and that’s why I came back. I think the guys enjoy when I pitch. I think sometimes I’m an amusement for them also.”

Why an amusement?

“I’m old, I guess,” Pettitte shrugged.

He’s old, but he’s back, striking out hitters at a better pace than even in his prime. Today, Pettitte said he made a small adjustment with his two-seamer — didn’t go into specifics, but he said he figured it out in the bullpen and carried it into the game — and that helped him control both sides of the plate. His cutter acts more like a slider this days, it was as effective as ever.

“I don’t really try to strike guys out,” Pettitte said. “I feel like I’m able to keep guys off balance an awful lot right now. My command was just really good tonight. I only left a couple of balls over the heart of the zone all night long. I’ve been real happy with my command and the feel of all my pitches. I didn’t think it would come back so quick.”

When he came out of the game and disappeared into the dugout, Pettitte gave a small fist pump, a tiny gesture, especially compared to the roaring ovation from the Yankee Stadium crowd. They came to see one of the finest pitchers in franchise history, and they certainly saw him.

“You have a memory of what a guy is like,” Joe Girardi said. “You say, you know what, he took a year and a half off, I don’t think he would come back if he didn’t think he could do it. So you just say, it’s Andy.”

• I know, I know, Martin’s a terrible player who’s not Jesus Montero and everyone hates him. But he’s hitting .391 since the beginning of the previous road trip, and tonight he delivered the big blow with his fourth-inning grand slam. It’s not much, but his batting average is up to .211 for the season. “Any time you get a shutout, you feel like you’ve done what you’re supposed to do as a catcher,” Martin said. “If you can contribute, hit a home run — a grand slam — against a tough pitcher, that’s even better.”

• Last time a Yankees player hit a grand slam from the No. 9 spot in the order was Francisco Cervelli in Texas last season. He hit it off Cody Eppley.

• Three of the Yankees past four hits with the bases loaded have been grand slams.

• After being hit by a pitch in the seventh, Robinson Cano had X-rays that came back negative. Jayson Nix replaced him at second base. “He was a little sore, a little stiff, so I think he’ll be a player for us tomorrow,” Girardi said.

• Cano went 2-for-3 off James Shields and is now a career .415 hitter against him.

• Here’s what Pettitte said about the improvements to his two-seam fastball: “I’ve got a little something that Larry (Rothschild) told me in my bullpen that I thought was going to help me. You don’t know whether to trust it or not during the game but then when you threw it and start seeing results you start getting confidence in it. It worked out good tonight.”

• Asked for more specifics of what he changed about the two-seamer, Pettitte said, “Sometimes if you get a thought in your head, it helps you. Larry helped me with that a little bit.” Not sure exactly what that means, but there you have it.

• Girardi said he’s been most impressed by Pettitte’s stamina at this point. Pettitte’s pitched through the seventh inning in each of his past four starts. Tonight he faced one batter in the eighth. It was, of course, a strikeout. “I was getting tired, there’s no doubt,” Pettitte said. “I get tired for sure out there. But, if you can just stay within yourself and not try to overthrow and realize my stuff might not be quite as sharp or my velocity might not be what it was in the first few innings, keep it out of the heart of the plate and you’ve got a chance to get them out.”

• Martin on his approach on the grand slam: “When you’re down 0-2 against Shields, you’re not thinking about hitting a homer. That was the last thing that was on my mind. I just got a good pitch out over the plate, really just trying to protect, and it just found some barrel for me. Next thing you know, it was in the bleachers.”

• Pettitte turns 40 next Friday. “It’s all in your mind, right?” Pettitte said. “Raul (Ibanez) told me he felt he’s alive still. He turned 40 the other day in Detroit and he goes, ‘It ain’t that bad.’”

• Pettitte’s reaction when told that his son Josh posted “Pops is dealing” on Twitter: “Great. Ok. Yeah. That’s good. Get rid of that.” Sorry, Josh.